The purpose of the proposed research is to take advantage of several existing datasets to address important research questions related to sexual activity in non-patient based samples of mid-aged women. It is generally thought that sexual activity declines with age. For women, however, there is some controversy over the relative contribution of menopause to this decline. Kinsey et al. and Masters and Johnson argued that changes in sexual activity for women were largely explained by the decline in sexual functioning in their male partners. More recent researchers attribute changes in women's sexual activity to declining estrogen levels. It is unclear, however, which (if any) aspects of sexual activity are affected by lowered estrogen levels and whether these changes are inevitable. Conclusions in this area have been hampered by numerous methodological limitations of the research. The research is often cross- sectional and/or based on patient populations. Often only a few aspects of sexuality are studied, few other variables are included, and/or the sample sizes are quite small. It has therefore not been possible to determine the relative contributions of age, hormones, and other factors (e.g., psychosocial, medical, partner characteristics) to changes in sexual activity for women. The existing datasets that will be used to address the research questions consist of a longitudinal study of transmenopausal changes in women (AGO3111, AG04673, and AG11431). The multidisciplinary team of investigators consisting of epidemiologists, psychologists, statisticians, clinicians, and endocrinologists are all familiar with these datasets. The longitudinal nature of the sample and the extensive data collected, will provide for the first time the ability to examine changes in various aspects of sexual activity (i.e. interest, frequency, satisfaction, difficulties) during the perimenopausal years as well as in other biological (including hormones) and psychological variables, lifestyle, and partner characteristics.